Ecological aspects of red squirrel (Sciurus vulgaris) dreys in city parks

Abstract

Modified habitats often pose challenges to native fauna. Red squirrels (Sciurus vulgaris) successfully inhabits territory of the cities. However research on quite abundant red squirrel populations in urban parks of Lithuania was lacking. The investigation was carried out in two city parks (area of Giruliai park 152 ha, Pasaku park forest - 31 ha) in Vilnius, Lithuania. Both areas were mainly coniferous, dominated with pine (Pinus sylvestris). Drey (N = 415) counts were done in February and March 2014-2016. Dreys were found in eight tree species. The red squirrels' dreys were mainly built in most widespread tree species: pine (84.8% of all dreys) and birch (8.1%). Most of the found dreys were built on the side branches at the stem (47.7%). 21.8% of the dreys were built on the branches further from the stem, 18.5% on the top branches and 12% in the stem fork-off. Most of the dreys were set in the southern exposition (33.9%). Average number of red squirrels in both parks in 2014-2016 was 0.20±0.01 squirrels/ha, the average number of dreys - 0.75±0.05 dreys/ha. The population of urban red squirrels in Vilnius city parks can be regarded as stable and having medium abundance, which is supported by supplementary feeding.